Crass practiced their "direct action" philosophy by spray-painting stencilled graffiti messages around the London Underground system and on advertising billboards, coordinating squats, and organising political action. The band also expressed its ideals by dressing in black, military surplus-style clothing and using a stage backdrop which amalgamated several "icons of authority" (including the Christian Cross, the swastika and the Union Flag) and an Ouroboros.   Wikipedia